1. Technical Field
The present invention relates to a semiconductor device.
2. Description of the Related Art
A known configuration of a semiconductor device has a p-type semiconductor layer and an n-type semiconductor layer connected with the p-type semiconductor layer. An electrode layer formed on the semiconductor layer of this semiconductor device is required to suppress the contact resistance, while ensuring the adhesiveness to the semiconductor layer. In order to meet this requirement, one proposed technique employs an electrode of a layered structure where an aluminum (Al) layer is formed on a titanium (Ti) layer as the electrode layer formed on the n-type semiconductor layer mainly made of gallium nitride (GaN) (see, for example, JP H07-45867A). Another proposed technique employs an electrode of a layered structure where a gold (Au) layer is formed on a nickel (Ni) layer as the electrode layer formed on the p-type semiconductor layer mainly made of gallium nitride (see, for example, JP H09-64337A).